How to retain values created using Lag function

[BalajiBollu]

Hi I have created a dataset with some sample values like below;

data a;
input x @@;
datalines;
1 2 0 0 3 4 5 0 0 0 6
;

Now i need to create another variable x1 where the non zero value of x should retain instead of 0's. The output i am looking for is

1 2 2 2 3 4 5 5 5 5 6.

I tried using lag function but i am not able to retain it if it has more than one 0 successively. Any help?

[Kurt_Bremser · Accepted solution]

You've already found the right word: retain.

The code should look like this:

data want;
set have;
retain _x 0;
if x ne 0
then _x = x; * this will always keep the last non-zero value;
else x = _x; * and this overrides the zeroes;
drop _x;
run;

If you need to do it for groups, the init of _x to 0 has to be done at first.group instead of in the retain statement.

[BalajiBollu]

Thanks KurtBremser. This is working

[novinosrin]

data a;
input x @@;
datalines;
1 2 0 0 3 4 5 0 0 0 6
;

data want;
set a;
_iorc_=ifn( x=0 and lag(x) ne 0 ,lag(x),_iorc_);
if x=0 then x=_iorc_;
run;